Introduction to the Special Issue of Continental Shelf Research on ‘The application of acoustics to sediment transport processes’

Sediment dynamics in coastal waters has relevance to a broad spectrum of marine science and engineering. Through the processes of accretion, erosion and transport, sediments define our coastlines, marine habitats, and nearshore recreation zones. Seabed sediments critically affect the stability of marine structures, shoreline protection and development, and navigation in coastal waters. Sediments act as reservoirs for nutrients and contaminants and as regulators of light transmission, thereby impacting significantly on water chemistry and primary production. Thus, predicting sediment transport, erosion and deposition is of great practical importance on a global scale, but is also very challenging. The challenge is associated in part with the complex and often non-linear interactions among combined forcing by waves and currents, the dynamic response of the bed, and sediment size and type, as well as the fundamental role of turbulence. Part of the challenge has also been the absence, historically, of suitable technologies for making the comprehensive measurements needed to adequately test or validate the models.